1. Field of the Invention
The present invention relates to an electronic timepiece using a plurality of light-receiving elements for receiving signal inputs.
2. Description of the Prior Art
A typical signal input device for a conventional electronic timepiece includes an external operation member such as a crown or button, and a switch controlled by the external operation member. Japanese Patent Publication No. 56-23114 describes another conventional signal input device wherein an external operation member extending through the watch case is not used to provide a waterproof mechanism, a light-receiving element is arranged inside the watch case, and light incident on the light-receiving element is externally controlled.
Since the conventional signal input device with a light-receiving element does not use an external operation member extending through the watch case, reliability of the waterproof effect can be improved, and a low-profile construction can be achieved. In addition, the number of components is decreased, making it low cost, along with many other advantages provided by this signal input device. However, since natural light is used as an input means, malfunction in the normal operation state causes some problems. In order to prevent such malfunction, complex input conditions must be satisfied. However, a signal input device of this type becomes difficult to operate if such complex input conditions ae set to completely prevent malfunction.